History

Syringomyelia usually progresses slowly; the course may extend over many years. The condition may have a more acute course, especially when the brain stem is affected (i.e., syringobulbia). Syringomyelia usually involves the cervical area. Symptomatic presentation depends primarily on the location of the lesion within the neuraxis. Clinical manifestations are discussed in the sections that follow.

Sensory

Syrinx interrupts the decussating spinothalamic fibers that mediate pain and temperature sensibility, resulting in loss of these sensations, while light touch, vibration, and position senses are preserved (dissociated sensory loss).

When the cavity enlarges to involve the posterior columns, position and vibration senses in the feet are lost; astereognosis may be noted in the hands.

Pain and temperature sensation may be impaired in either or both arms, or in a shawllike distribution across the shoulders and upper torso anteriorly and posteriorly.

Dysesthetic pain, a common complaint in syringomyelia, usually involves the neck and shoulders, but may follow a radicular distribution in the arms or trunk. The discomfort, which is sometimes experienced early in the course of the disease, generally is deep and aching and can be severe.

Motor

Syrinx extension into the anterior horns of the spinal cord damages motor neurons (lower motor neuron) and causes diffuse muscle atrophy that begins in the hands and progresses proximally to include the forearms and shoulder girdles. Clawhand may develop.

Respiratory insufficiency, which usually is related to changes in position, may occur.

Autonomic

Impaired bowel and bladder functions usually occur as a late manifestation.

Sexual dysfunction may develop in long-standing cases.

Horner syndrome may appear, reflecting damage to the sympathetic neurons in the intermediolateral cell column.

Extension of the syrinx

A syrinx may extend into the medulla, producing a syringobulbia.
[6, 7] This syndrome is characterized by dysphagia, nystagmus, pharyngeal and palatal weakness, asymmetric weakness and atrophy of the tongue, and sensory loss involving primarily pain and temperature senses in the distribution of the trigeminal nerve.

Rarely, the syrinx cavity can extend beyond the medulla in the brain stem into the centrum semiovale (syringocephalus).

Lumbar syringomyelia can occur and is characterized by atrophy of the proximal and distal leg muscles with dissociated sensory loss in the lumbar and sacral dermatomes. Lower limb reflexes are reduced or absent. Impairment of sphincter function is common.

Other manifestations

Painless ulcers of the hands are frequent. Edema and hyperhidrosis can be due to interruption of central autonomic pathways.

Carroll AM, Brackenridge P. Post-traumatic syringomyelia: a review of the cases presenting in a regional spinal injuries unit in the north east of England over a 5-year period. Spine. 2005 May 15. 30(10):1206-10. [Medline].

Mueller D, Oro' JJ. Prospective analysis of self-perceived quality of life before and after posterior fossa decompression in 112 patients with Chiari malformation with or without syringomyelia. Neurosurg Focus. 2005 Feb 15. 18(2):ECP2. [Medline].